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Set MRM quantifiers

Warning

To process multiple reaction monitoring (MRM) data, the MRM service of mzmine is required. This feature is included in the mzmine PRO subscription. Academic program and other users can reach out to inquire access options.

MRM → Set MRM quantifiers

The MRM to Scans module automatically sets the most intense transition as the quantifier ion. However, some MRMs may be more challenging and shall be quantified by a different transition. Here, the Set MRM quantifiers module can help to select the specific ions needed for accurate quantification.

Tip

You can look at the current quantifier ion mass by enabling the "Feature:MRM transitions" in the feature table by selecting the small "+" in the upper right corner of the feature table. img.png

Parameters

Feature lists

Select the feature lists in which the quantifier ion shall be re-set.

Quantifier ion list

Select a file that contains the necessary quantifier ion information in a tabular format (comma, tabulator, semicolon delimited). The file may contain additional columns that are not necessary here.

Tip

Since the quantifier ion list only selects the necessary information from the file, you can use the same file for the Local compound database search or in the MRM wizard.

Column headers

Set the column headers in the quantifier ion list file. mzmine will search for the respective headers in the file and read the data from it. The file may contain additional columns that are not necessary here. All columns (Q1 m/z, Quantifier m/z, RT) are necessary.

RT tolerance

Set an RT tolerance between the entry in the quantifier ion list and the detected RT in the feature list. This is the option to set different quantifiers to different features of the same precursor m/z.

m/z tolerance

Set an m/z tolerance between the entry in the quantifier ion list and the m/z in the feature list. Usually, the m/z is the set m/z in the acquisition software and does not fluctuate as it would in HRMS, where the actual m/z value is part of the detection.


Robin Schmid, Steffen Heuckeroth